Question 1

Which of the following best describes the main structural difference between the cell walls of Gram-positive and Gram-negative bacteria?

Accepted Answer

Gram-positive bacteria have a thick peptidoglycan layer and teichoic acids, while Gram-negative bacteria have a thin peptidoglycan layer and an outer membrane containing lipopolysaccharides.

Question 2

A patient is diagnosed with pneumonia caused by Streptococcus pneumoniae. Which structure on the bacterial cell most directly contributes to its ability to evade phagocytosis by immune cells?

Accepted Answer

Capsule (a type of glycocalyx)

Question 3

Which of the following best explains why Mycoplasma species are resistant to antibiotics such as penicillin that target cell wall synthesis?

Accepted Answer

Mycoplasma lack a cell wall and instead have sterols in their plasma membrane.

Question 4

Which of the following arrangements describes a chain of rod-shaped bacteria?

Accepted Answer

Streptobacilli

Question 5

A bacterium is observed to move in a corkscrew-like fashion. Which structure is responsible for this type of motility?

Accepted Answer

Axial filament (endoflagellum)

Question 6

Which of the following is a function of the bacterial nucleoid?

Accepted Answer

It contains the cell's genetic information in the form of a circular DNA molecule.

Question 7

Which of the following best describes the process of group translocation in prokaryotic cells?

Accepted Answer

A substance is chemically modified as it is transported across the membrane, requiring a transporter protein and phosphoenolpyruvic acid (PEP).

Question 8

Which of the following inclusions would you expect to find in a photosynthetic bacterium that allows it to fix carbon dioxide?

Accepted Answer

Carboxysomes

Question 9

A laboratory technician stains a bacterial sample and observes pink cells under the microscope after a Gram stain. Which of the following statements best explains this result?

Accepted Answer

The bacteria are Gram-negative because the alcohol step dissolved the outer membrane and allowed the crystal violet-iodine complex to wash out.

Question 10

Which of the following best describes the function of fimbriae in bacteria?

Accepted Answer

Fimbriae allow bacteria to adhere to surfaces and are important in the formation of biofilms.

Question 11

Which of the following is a key piece of evidence supporting the endosymbiotic theory for the origin of mitochondria and chloroplasts?

Accepted Answer

Mitochondria and chloroplasts contain circular DNA and 70S ribosomes similar to those of bacteria.

Question 12

Which of the following best explains why penicillin is more effective against Gram-positive bacteria than Gram-negative bacteria?

Accepted Answer

Gram-positive bacteria have a thick peptidoglycan layer that is directly accessible to penicillin, while Gram-negative bacteria have an outer membrane that blocks penicillin entry.

Question 13

A bacterium is placed in a hypertonic solution. What is the most likely outcome for the cell?

Accepted Answer

Water will move out of the cell, causing plasmolysis.

Question 14

Which of the following statements correctly compares prokaryotic and eukaryotic ribosomes?

Accepted Answer

Prokaryotic ribosomes are 70S, while eukaryotic cytoplasmic ribosomes are 80S.

Question 15

Which of the following best describes the function of the bacterial plasma membrane?

Accepted Answer

It acts as a selectively permeable barrier and contains enzymes for ATP production.

Question 16

A scientist observes a bacterium with a single flagellum at one end. What is the term for this flagellar arrangement?

Accepted Answer

Monotrichous and polar

Question 17

Which of the following is a correct statement about endospores?

Accepted Answer

Endospores are highly resistant structures formed by certain bacteria in response to nutrient depletion.

Question 18

Which of the following best describes the difference between simple diffusion and facilitated diffusion across a bacterial plasma membrane?

Accepted Answer

Simple diffusion does not require membrane proteins, while facilitated diffusion requires specific transporter proteins.

Question 19

Which of the following is a function of teichoic acids in Gram-positive bacteria?

Accepted Answer

They help regulate the movement of cations and provide antigenic specificity.

Functional Anatomy of Prokaryotic and Eukaryotic Cells: Structure, Function, and Comparison

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